The invention pertains to methods of treating dielectric materials with oxygen, and in particular embodiments pertains to methods of forming capacitor constructions.
Dielectric materials are incorporated into numerous semiconductor constructions, including, for example, capacitor constructions. The dielectric materials will frequently comprise an oxide, such as, for example, one or more of silicon dioxide, silicon oxynitride, and tantalum pentoxide. A difficulty that can occur in forming such dielectric materials is that there can be regions within the materials which are oxygen deficient. For instance, there can be regions within a tantalum pentoxide material in which the ratio of tantalum to oxygen is higher than that which exists in the stoichiometric material Ta2O5. Such regions have a lower dielectric constant than would exist if the regions had sufficient oxygen to reach the stoichiometry of Ta2O5.
It is typical for a dielectric material to comprise oxygen-deficient regions interspersed within a material that predominantly is not oxygen deficient. For instance, it is common for Ta2O5 to be formed under conditions in which the majority of the material comprises the stoichiometry of Ta2O5, and in which oxygen-deficient regions are interspersed throughout the tantalum pentoxide material. The oxygen-deficient regions can disrupt a uniformity of the physical properties of the tantalum pentoxide material. For instance, the oxygen-deficient regions can disrupt the uniformity of dielectric strength throughout the tantalum pentoxide material. Disruption of the physical properties of the tantalum pentoxide material can cause inconsistencies in device performance from semiconductor devices incorporating the dielectric material, which can reduce performance of the devices and, in particularly problematic cases, can render the devices inoperable.
A solution to the problem of having oxygen-deficient regions within a dielectric material is to expose the material to an oxidant to cure oxygen deficiencies within the material. For instance, dielectric materials can be exposed to ozone to cure oxygen deficiencies within the materials. A difficulty which is frequently encountered is that the oxidants do not cure enough of the oxygen deficiencies within a dielectric material to acceptably overcome the above-described problems associated with having oxygen deficiencies interspersed throughout a dielectric material. Accordingly, it would be desirable to develop new methods for reducing the oxygen deficiencies within a dielectric material, and it would be particularly desirable if such methods could entirely eliminate oxygen deficiencies throughout a dielectric material.
In one aspect, the invention encompasses a method of treating a predominantly inorganic dielectric material on a semiconductor wafer. A laser is utilized to generate activated oxygen species. Such activated oxygen species react with a component of the dielectric material to increase an oxygen content of the dielectric material.
In another aspect, the invention encompasses a method of forming a capacitor construction. A first capacitor electrode is formed to be supported by a semiconductor substrate. A dielectric material is formed over the first capacitor electrode. A precursor is provided at a location proximate the dielectric material, and a laser beam is focused at such location. The laser beam generates an activated oxygen species from the precursor. The activated oxygen species contacts the dielectric material. Subsequently, a second capacitor electrode is formed over the dielectric material.